#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>


int main(int argc, char *argv[])
{
    int fd,ret;
    unsigned char buf[1];

    fd=open(argv[1], O_RDWR);
    
    buf[0]=atoi(argv[2]);
    ret=write(fd,buf,sizeof(buf));

    close(fd);
}